Although many different species seem to communicate in different ways, human communication seems especially complex and rich in its ability to convey complex and abstract information. Two functions of communication are social and practical.

Communication, whether by gestures, speech, or writing is the technology that allows society to function in a cohesive and cooperative manner. For example, the earliest settled agricultural communities need to communicate in order to cooperate on irrigation, especially in such cases as Egypt where the annual Nile flood requires a complex system of irrigation channels.

Specialization of labor depends on mechanisms of exchange, which require some form of communication or negotiation; even bartering using gesture when one has no languages in common is a form of communication.